Diffractive display and method utilizing reflective or transmissive light yielding single pixel full color capability

ABSTRACT

The present invention is directed to a diffractive display suitable for presenting graphic and the like displays. Broadly, the novel display is realized from a diffraction pattern (132) carried by (e.g. embossed) a film or element (138) connected to an energy source which is energizable for movement of the film (138). Movement of the patterned film (138) generates a display using the diffracted light from the embossed pattern (132). Electroactive films are known in the art, including, for example, piezoelectric films, electrostrictive films, electromotive films, and electrostatic films. Magnetoactive films also are known in the art. Any of these films (138) can carry the diffraction pattern (132) and be energized for movement to generate from the resulting diffracted light.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of PCT/U.S. 94/07584, filed Jul. 12, 1994, anda continuation-in-part of application Ser. No. 08/093,255, filed Jul.16, 1993, now abandoned, the disclosure of which is expresslyincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to displays and more particularly to adiffractive display (reflective or transmissive) wherein each pixelexhibits a full range of diffracted wavelengths (e.g., full range ofcolors) by a novel diffractive technique.

The art is replete in proposing graphics displays which utilize, forexample, bimorph elements or, simply, bimorphs, or equivalents. Abimorph is a device manufactured with two strips of piezoelectric filmwhich are fastened together and which have electrodes allowingelectrical fields of the proper polarity to be applied to the film tocause an electrostrictive effect to occur. Such electrostrictive effectcan be an in-plane elongation or contraction, or an out-of-planedeflection of one end of the film when the opposite end is secured.

U.S. Pat. No. 4,331,972 proposes a light valve comprising a pair ofelements of transparent material, each comprising a diffraction gratingof light periodicity facing each other with parallel grating lines. Suchlight valve is termed a bigrate in this patent. The transmission oflight through the bigrate will depend on the relative position of thepair of gratings in the direction perpendicular to the grating lines.One of the gratings may be embossed on a bimorph film of polyvinylidenefluoride and moved by the application of a voltage thereto. One strip,then, may be moved relative to the other in response to an electricalsignal to control the zero diffraction or the light transmission from notransmission to full transmission, or any desired intermediatetransmission. Three different superimposed bigrated light valves areused for achieving the three different colors required for a colordisplay, viz., cyan, magenta, and yellow.

U.S. Pat. No. 5,067,829 proposes to steer light beams by passing thelight beams through optically transparent elastic material which arebent under the application of a voltage which bending or deformationcauses the change in the angle at which the light beam intercepts thesurfaces of the optically transparent layers.

U.S. Pat. No. 5,052,777 utilizes a bimorph as a shutter to pass or blocklight coupling therethrough. Such bimorph shutters permit light, such astransmitted through optical fibers, to be coupled through the bimorphlight valves to an observer for generating graphic displays.

U.S. Pat. No. 4,274,101 discloses a laser recorder that utilizes apiezoelectric bimorph focal length vibrator.

U.S. Pat. No. 5,126,836 proposes a television display wherein a whitelight source emits a beam onto a plurality of dichroic mirrors whichsplit the beam into three beams of primary colors, then reflects theprimary beams onto three deformable reflective surfaces which may bepiezoelectric crystals, which again reflect the beams through slits in anon-reflective surface, thereby modulating the intensity of the beams.U.S. Pat. No. 4,415,228 proposes a bimorph light valve also as does U.S.Pat. No. 4,234,245.

Additional proposals include Stein, et al, "A Display Based onSwitchable Zero Order Diffraction Grating Light Valves", Advances inDisplay Technology V, SPI vol. 526, 105-112 (1985), which propose a flatpanel display which utilizes a matrix of line addressable light valvesback-lighted with a partially collimated source. The basic pixel elementof the display is an optical switch based on the zero order ofdiffraction by two aligned transmission phase gratings. The transmissionof light is modulated by mechanically displacing one grating withrespect to the other by one-half of the grating. A bimorph is used forthis purpose.

Finally, another proposal is by Gale, et at., "Diffractive Diffusers forDisplay Application", Current Developments in Optical Engineering andDiffraction Phenomena, SPIE vol. 679, 165-168 (1986), which proposediffractive optical diffusers for display applications wherein thediffusers can be fabricated by laser beam writing techniques.

While the foregoing techniques function to some degree to providegraphic displays, there still exists a real need in the art to make suchdisplays economical and practical, especially when produced in largevolume, and to be fully addressable for providing complex graphicsdisplays.

BROAD STATEMENT OF THE INVENTION

The present invention is directed to a diffractive display suitable forpresenting graphic and the like displays. Broadly, the novel display isrealized from a diffraction pattern carried by a film or element (e.g.,an embossed film) connected to an energy source which is energizable formovement of the film. Movement of the patterned film generates a displayusing the diffracted light from the embossed pattern.

Electroactive films are known in the art, including, for example,piezoelectric films, electrostrictive films, electromotive films, andelectrostatic films. Magnetoactive films also are known in the art. Anyof these films can carry the diffraction pattern and be energized formovement to generate from the resulting diffracted light.

One desirable film is a piezoelectric film which film is connected to anenergy source for its movement. The movement of said embossed filmgenerates a display using the diffracted light from the embossedpattern. Preferably, multiple layers of the piezoelectric films areformed into a bimorph element which bears the diffractive pattern forforming the novel display. Preferably, also, the piezoelectric filmsused alone or in a bimorph element are elastic, i.e., they return totheir original position after movement by the energy source which mostprobably is an electrical source.

One embodiment of the piezoelectric diffractive display is atransmissive diffractive display. This display includes an outertransparent rigid member having an outer surface and an inner surface,wherein this member restricts reflected energy incident on its innersurface. A discrete lens element has an apparent outer surface and anapparent inner surface and is adjacent to the outer transparent rigidmember. A rigid opaque spacer has an outer surface and an inner surface,has an aperture in registration with said discrete lens element, and isdisposed in adjacency to the lens element apparent inner surface. Atransmissive discrete bimorph element is in registration with the rigidopaque spacer aperture, wherein the discrete bimorph element has aninner surface and an outer energy diffractive surface adjacent to thespacer aperture which diffractive surface bears a diffraction gratingfor diffracting energy passed therethrough when said bimorph element isin a relaxed state. The discrete bimorph element is connected to asource effective to generate selected excited states therefor whereinsaid bimorph element is physically displaced from its location in arelaxed state. The bimorph element transmits a different diffraction ofthe energy passed therethrough when said bimorph element is in anexcited state. Thus, energy transmitted through the diffraction gratingis diffracted and then passed through said aperture through said lenselement which focuses said diffracted energy onto the transparent rigidmember outer surface.

Another piezoelectric film embodiment is a reflective diffractivedisplay. This display includes an outer transparent rigid member havingan outer surface and an inner surface. This outer member passes incomingenergy incident on its outer surface, but restricts reflected energyincident on its outer surface, the underside of which, for example, hasbeen coated. A discrete lens element has an apparent outer surface andan apparent inner surface and is disposed adjacent to the outertransparent rigid member. This lens element focuses energy passedthrough the outer transparent rigid member and incident thereon from thelens element apparent outer surface onto the outer transparent rigidmember with such energy then reflected back through the lens element. Arigid opaque spacer has an outer surface and an inner surface, has anaperture in registration with the discrete lens element, and is disposedin adjacency to the lens element apparent inner surface. A bimorphelement is in registration with the rigid opaque spacer aperture. Thisbimorph element has an outer energy reflecting surface adjacent to thespacer aperture which reflecting surface bears a diffraction gratingwhich permits reflectance of selected diffracted energy incident on theouter bimorph element surface when said bimorph element is in a relaxedstate. The bimorph element is connected to a source effective togenerate selected excited states therefor wherein said bimorph elementis physically displaced from its location in a relaxed state. Thebimorph element permits reflectance of different diffracted energyincident on the bimorph element outer surface when the bimorph elementis in an excited state. Thus, energy incident on the transparent rigidmember outer surface passes therethrough and is directed through saidaperture and incident on the diffraction grating. Selected energy thenis reflected back from said diffraction grating through the aperturethrough said lens element which focuses the selected energy onto thetransparent rigid member outer surface.

Alternatively, a holographic diffractive element (HDE) can be createdwith a unique geometry such that it reflects/transmits a focusedspectrally pure real image a short distance in front of it onto adiffuse surface. This unique geometry for the construction of thehologram provides a "self focusing" pixel. Thus, when a reference beamstrikes the HDE in the conjugate direction (from the opposite side in adirection towards the original source), a real image of a slit (e.g.,aperture of the opaque spacer) is reconstructed at a distance d₁ fromthe HDE. The HDE, which also contains a diffraction pattern and movementforce (for example, a bimorph with diffraction pattern), is placed adistance d₁ from the transparent rigid member. When a reconstructionbeam strikes the HDE, the angle of incidence will result in a colorimage of the slit being projected as a diffuse "dot" onto the rigidtransparent member for viewing by an observer. As the HDE is bent, theincidence angle will vary and so will the color projected. A matrix ofHDEs results in a display of discreet colored pixels.

While selected energy or wavelengths of energy can range anywhere fromthe infrared to the ultra-violet region of the spectrum, advantageously,the visible spectrum will be utilized wherein each patterned element,for example, piezoelectric element/aperture/lens element combinationwill be capable of providing "single pixel" full color. Moreover, eachsuch element is separately addressable so that a matrix of such elementsare able to generate graphic displays that can be static or dynamic.Advantageously, the diffraction grating can be holographic in nature ascan the lens elements. A facile method of constructing the inventivedisplay also is disclosed. Such technique involves the manufacture ofdisplay modules which can be inter-connected for making displays ofvarying size.

Another embodiment utilizes magnetic moment actuator to provide out ofplane deflection. Still another embodiment uses the forces on a currentcarrying conductor which is immersed in an orthogonal magnetic field toprovide out of plane deflection.

Advantages of the present invention include a diffractive display thathas no moving parts, but for the elements which merely are physicallydisplaced between a relaxed state and an excited state(s). Anotheradvantage is a diffractive display that is relatively simple inconstruction, yet provides remarkably brilliant reflected colors. Yetanother advantage is a diffractive display which effectively providessingle pixel full color for visual graphic displays. Yet anotheradvantage is a diffractive display that can be manufactured modular forvarying the size of the display. Yet a further advantage is the abilityto individually address each element in a matrix of such elements forproviding dynamic and animated graphic displays. Yet another advantageis the ability to generate displays in a reflective or a transmissivemode of operation. A still further advantage is that the display has awide view angle. These and other advantages will be readily apparent tothose skilled in the art based upon the disclosure contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the precepts and advantages of the presentinvention, reference is made to the description that follows taken inconjunction with the accompanying drawings in which:

FIG. 1 is a side view of a bimorph element shown in three differentpositions for generating three different colors;

FIGS. 2a-c illustrate how a physical structure of a fixed index ofrefraction can create an apparent variation in the index of refraction;

FIGS. 3a-d are schematic representations of the operation of adiffractive bimorph element operation in the transmission mode;

FIGS. 4a-d are schematic representations of the operation of adiffractive pixel operation in the transmission mode;

FIGS. 5a and b are schematic representations of a bimorph elementconnected in parallel or series to voltage source;

FIG. 6 is a schematic representation of a diffractive optical element(DOE) operating in either a daytime or a nighttime mode;

FIG. 7 is a partial cross-section of the novel display in a reflectivemode of operation;

FIG. 8 is an overhead plan view of the novel reflective display;

FIG. 9 is a side elevational view of one of the bimorph elements of thenovel display for either reflective or transmission mode of operation;

FIG. 10 is a partial overhead plan view of a layer of bimorph elementsfor either reflective or transmission mode of operation;

FIG. 11 is a side elevational view of a piezoelectric film elementembodiment for either reflective or transmission mode of operation;

FIG. 12 is a side elevational view of yet another bimorph elementembodiment for either reflective or transmission mode of operation.;

FIG. 13 is a schematic representation of the construction of an HDE;

FIG. 14 is a side elevational view of the HDE of FIG. 13 being used todisplay colors;

FIG. 15 is a side elevational view of a pair of HDEs being projectedthought apertures for viewing discreet color pixels;

FIG. 16 is a side elevational view of an embossed element whose end ismoved by plunger 134 which may be electrostrictive or magnetostrictive;

FIG. 17 is a side elevational view of an HDE assembly which operates onthe principle of magnetic moment using permanent magnets whose poles arein a plane parallel to the plane of the relaxed diffraction grating;

FIG. 18 is a side elevational view of an HDE assembly which operates onthe principle of magnetic moment using permanent magnets whose poles areperpendicular to the plane of the relaxed diffraction grating;

FIG. 19 is a side elevational view of an HDE assembly which operates onthe magnetomotive principle F=B×L×i, using permanent magnets whose polesare perpendicular to the plane of the relaxed diffraction grating;

FIG. 20 is the HDE of FIG. 19 with sound generation capability added;

FIG. 21 is a sectional view taken along line 21 A--A of FIG. 20; and

FIG. 22 is a plan view of the coils common to the HDE assembliesdepicted at FIGS. 17-19.

The drawings will be described in detail below.

DETAILED DESCRIPTION OF THE INVENTION

Much of the following description is of a piezoelectric or bimorphelement used in the diffraction of energy by its movement; however, suchdescription is illustrative of the invention and not a limitation of theinvention as electrostrictive, electromotive, electrostatic, andmagnetostrictive elements similarly can carry the diffraction gratingand be moved to diffract incident energy for generating a display.

With respect to the reflective mode of operation of the noveldiffractive display, embossing a diffraction grating or rainbowholographic diffraction grating onto a reflective piezoelectric materialdiffracts a particular color when illuminated by a broad band source ata particular angle. Application of a voltage to the piezoelectricmaterial will cause the material to move and, thus, change the angle ofthe incident light to the diffraction grating. This will cause the beamdiffracted at a given angle to change its wavelength. For a broad bandvisible light source (although the present invention is equallyapplicable to ultra-violet and infrared wavelengths of energy), it ispossible to cause a pixel to reflect the colors red, green, and blue, asa function of the applied voltage to the embossed piezoelectricmaterial. For present purposes, a pixel is defined as bimorph materialon which is embossed a holographic diffraction grating.

In order to achieve color uniformity and a wide field of view, thisgrating should be a hologram of, e.g., ground glass, photographic film,or the like. The diffracted color is determined by the grating equation:

    λ=d(sin i+sin δ)

where,

λ=wavelength of diffracted light (microns)

d=grating spacing of one cycle (microns)

i=angle of incidence from plate normal (degrees)

δ=angle of diffraction from plate normal (degrees)

For a fixed δ and a fixed d, the wavelength will vary with changes in i.FIG. 1 diagrammatically displays three positions of a grating on bimorph10 reconstructing red, green, and blue for position 12, position 14, andposition 16, when incident light 18 impacts bimorph 10 with itsdiffraction grating resulting in diffracted light 20 being reflectedtherefrom. In order to achieve diffracted light 20, the surface ofbimorph 10 upon which reference light beam 18 strikes must be bothreflective and contain a diffraction grating. By varying the position ofbimorph 10, the diffracted energy (e.g. color) reflected can becontrolled.

With respect to the transmission mode of operation of the noveldiffractive display, some piezoelectric films, such as polyvinylidenefluoride (PVDF or PVF₂) are optically transparent. A holographic orother diffraction pattern, then, can be embossed into the materialdirectly, for example. The transmitted light diffracts due to theapparent changes in the index of refraction across the material due tograting thickness (spacing as a function of bimorph bend or stretch)variations. This apparent index of refraction change is illustrated inFIG. 2. If the size variations of the grating structure are smaller thana wavelength of light, the average index of refraction will be takenacross the material over the length of the light wavelength asillustrated at FIG. 2c. Thus, an effective modulating index ofrefraction (η=1.2 as at item 23 ) occurs across the surface of amaterial which has a fixed index of refraction (η=1.4 as at item 21 ).The larger the fixed index of refraction of the material, the greaterthe effective modulation depth can be. For this reason, it may bedesirable to place a thin layer of a very high index of refractiontransparent material over top of the PVDF film and then emboss into thislayer to increase the depth of modulation and, thus, the diffractionefficiency. This grating may be formed into the film by embossing orholographically using a photographic emulsion.

This modulation mechanism in a holographically produced transmissiongrating is that the diffraction pattern produced holographicallyproduces dark and light areas in proportion to the intensity of theincident electric field. These dark and light areas are converted tovariations in the index of refraction of the material proportional tothe applied electric field by a process called "bleaching" which iscommonly used to dramatically increase the diffraction efficiency andproduce what is referred to as a "phase grating".

An electric field still must be applied across anelectrically-conductive bimorph element in order to get movement. Thisconductivity is achieved by applying a layer of a thin transparentconductive film to each side of the bimorph (TiO₂ or indium tin oxidebeing examples of such materials that are readily available).

When a fixed broad band light source illuminates this grating, aparticular color of light is diffracted at a particular angle accordingto the grating equation described above. Application of a voltage acrossthe bimorph will cause the bimorph to bend and change the angles i andδ. Since d is fixed, the wavelength changes in proportion to the angle.The resulting effect is that the illuminated bimorph appears to be acolor from the illuminating spectrum in proportion to the appliedvoltage as illustrated at FIGS. 3 and 4. In FIGS. 3a-d, source 25illuminates bimorph 29 which is connected to electrical source 27a-d,respectively. In FIG. 3a when no bias voltage is applied to bimorph 29,bimorph 29 diffracts energy from source 25, which is a suitablebroadband light source, to transmit green light therethrough. In FIG. 3bwhen source 27b generates a given voltage, bimorph 29 bends to position31 such that the source energy is transmissively diffracted to producered light. In 3c when source 27c generates a different given voltage,bimorph 29 bends to position 33 such that the source energy istransmissively diffracted to produce blue light. In FIG. 3d when source27d generates yet another voltage, bimorph 29 bends to position 35 orposition 37 such that the source energy is transmissively diffractedoutside the visible spectrum to effectively block all lighttransmission. In FIGS. 4a-d, the same diffraction transmission bimorpharrangement as that described in FIGS. 3a-d is illustrated, except thatdirectionally diffusive surface 39a and holographic optical element(holographic lens) 39b are placed on the output side of bimorph 29 toincrease the effective brightness of and, thus, the diffracted energyfrom bimorph 29.

Referring now to the bimorph elements or bimorphs in more detail, asingle layer of PVDF or other piezoelectric film deforms by a smallamount when subjected to an electric field. This deformation can beamplified to a very high magnitude using a bimorph configuration whichconsists of two piezoelectric films laminated together typically with anadhesive. When an excitation voltage is applied, one layer expands whilethe other layer contracts, resulting in the bimorph bending as anindividual structure. The motion amplitude ratio of a bimorphapproximates the ratio of its length to its thickness. Hence, amagnification of several thousand times can be obtained easily using,for example, a 5 μm thick PVDF bimorph. Thus, a simple bimorphconfiguration generates a large bending motion with low frictionallosses.

Experimentally and analytically, it is found that lateral deflection islinearly related to the applied electric field and load. The equationsgoverning the displacement, force generated, and voltage output of abimorph are: ##EQU1## where, V=applied voltage (volts)

F=generated force (newtons)

Δx=displacement (meters)

L, t, w=length, thickness, and width of film, respectively (meters)

Y=Young's modulus of the film (2×10⁹ N/m² for PVDF)

d₃₁, g₃₁ =piezoelectric strain and stress constants, respectively.

A bimorph is constructed using uniaxially-oriented PVDF or other filmwith surface uniformly metalized (for the reflective mode of operation)with conductive materials (e.g., aluminum ink) in two differentlamination configurations: parallel and series. FIGS. 5a and 5b show theparallel and series laminations, respectively, with the basic differencebeing the mode of lead attachment to voltage source V_(i). Bimorphelement 41 has electrically-conductive layers 43 and 45 laminated oraffixed thereto. In the parallel laminate in FIG. 5a, both films ofbimorph 41 stretch in the same direction resulting in a higher force butlower displacement Δx at the tip. In the series laminate in FIG. 5b, thefilms of bimorph 41 stretch in the opposite direction with respect toeach other leading to a lower force generation but increaseddisplacement Δx at the free end. Further information on bimorphs can befound in the following references which are expressly incorporatedherein by reference: Toda, et at., "Large Area Display Element UsingPFV₂ Bimorph With Double-Support Structure", Ferroelectrics, 1980, Vol.23, pp 115-120; Toda, et al., "Large Area Electronically ControllableLight Shutter Array Using PFV₂ Bimorph Vanes", ibid at pp. 121-124;Linvill, "PFV₂ Models, Measurements and Devices", id at Vol. 28, pp.291-296; Negran, et al., "A Clue to the Origin of Pyroelectricity inPFV₂ From the Low Temperature Behavior", ibid at p. 299; Willis, et at.,"The Structure of Electric-Field-Induced Layer Defects inSurface-Stabilized Ferroelectric Liquid Crystal Display Cells", SID 90Digest, pp 114-116; Kistner, et al., "Evaluation of a Small WearableDisplay", ibid at pp 136-139; and Reinke, "High Density Display/DriverInterconnections Using Anisotropic CAIS: (Conductive AdhesiveInterconnect System)", SPIE Vol. 1080, Liquid Crystal Chemistry,Physics, and Applications (1980).

A hologram or diffraction grating is embossed into, for example, a metallayer adhering to one side (for example, a common ground in a matrix oran array of bimorphs) which can be reflective (e.g., highly reflectivealuminum) or can be transparent (e.g., TiO₂, indium tin oxide, or thelike) for a reflective or transmission mode, respectively.Alternatively, the hologram or diffraction grating can be embossed intoa transparent film (e.g., Mylar® brand polyester) which is laminated,typically with a transparent adhesive, to the bimorph.

Holographic lenses are a particular type of holographic optical element(HOE) or diffractive optical element (DOE) which have the characteristicthat they operate by modifying light waves by the properties ofdiffraction rather than refraction which is used by conventional optics.In other words, a wavefront can be made to diverge or expand bydiffracting the wavefront with a microscopic spatially varying patternof dark and light areas or by spatially varying refractive indices, asopposed to conventional optics where light rays are bent strictly fromcontinuously varying macroscopic variation in the index of refraction.

Diffractive optics have the advantage that they are lighter, smaller,and can be less expensive to manufacture, and can be made to modifywavefronts in ways that would be impossible with conventional optics.However, they have the disadvantage for imaging applications that theyhave more severe chromatic aberrations than conventional optics. Sinceimaging is not required of the novel diffractive display, thisdisadvantage is of no moment.

The DOE described herein would collect collimated light from a specificangle or selected group of angles and focus that energy to a focalpoint. When coupled with a bimorph element (bimorph 50 in FIG. 7,described in detail below) as also described herein, the DOE focal pointis on surface 24 (FIG. 7) of outer rigid transparent member 22 (FIG. 7).Schematically, the DOE is illustrated at FIG. 6 where daytime referencebeam 47 strikes HOE/DOE 49 which focus the resulting transmitted energyat focal point 51 and where nighttime reference beam 53 strikes HOE/DOE49 which focus the resulting transmitted energy also at focal point 51.Further information can be found in the following references which areexpressly incorporated herein by reference: Hayford, "HolographicOptical Elements", Photonics Spectra, pp 77-79 (April 1982); and Fan, etal, "Color Coding Reproduction of Two-Dimensional Objects with RainbowHolography", Optical Engineering, October 1991, Vol. 30, No. 10,1625-1628.

With respect to a display that can be readily manufactured forimplementing the reflective diffractive technique described inconnection with FIGS. 7-12, reference initially is made to FIG. 7. Atthis point, much of the remaining description of the present inventionwill be with respect to use of incident sunlight (or an equivalentthereof) wherein the novel graphic display in a reflective mode ofoperation exhibits single pixel full color generation. It will beunderstood, however, that such description is by way of illustration andnot limitation since non-visible wavelengths of energy in theultra-violet and infrared areas of the spectrum can be efficiently andeffectively used by the novel display described herein, as can atransmission mode of operation. With respect to FIG. 7 in particular,outer transparent rigid member 22 most suitably will be glass, thoughtransparent plastics or ceramics could be used if desired. Rigidity oftransparent member 22 aids in making the entire display rigid. Outersurface 24 upon which incident light 26 strikes has been coated with anon-linear coating. Such non-linear coating allows light 26 to passthrough transparent rigid member 22 but will not permit reflected lightstriking inner surface 28 coming back through member 22 will beattenuated on top surface 24. It is on top surface 24 that the pixelinformation is generated, as represented at pixel 30. Non-linearcoatings, such as magnesium fluoride (MgF₂) and others, are well knownin the art.

Adjacent inner surface 28 of glass 22 is a matrix of discrete lenselements represented as lens elements 32-38. It should be understoodthat while only four lens elements are shown and only lens element 32will be described in detail, such lens elements are representative of amatrix of discrete lens elements of suitable size and packing density asis required for the particular display being manufactured.Advantageously, lens elements 32-38 can be made as holographic lenses inlayer 40. Each lens element needs to be complex because it is collectingincident light and focusing it on a bimorph element, and then focusingthe reflected selected light back onto outer surface 24 of rigid member22 for forming pixel 30. A description of the generation of suchholographic lens can be found in, for example: The SPIE HolographicsInternational Directory & Resource Guide, The Society of Photo-OpticalInstrumentation Engineers, Bellingham, Wash. (1993). Non-holographiclens elements commercially available include SMILE™ sphericalmicrointegrated lenses supplied by Coming Incorporated (Coming, N.Y.),and Monolithic Lenslet Modules supplied by Adaptive Optics Associates,Inc. (Cambridge, Mass.). The disclosures of these references areexpressly incorporated herein by reference.

While glass member 22 and lens element assembly 40 can be held togetherunder compression at their edges, it is desirable that no dead air spaceremain between these layers. Thus, in order to fill any dead air spacesand in order to keep these layers in their proper relationship to eachother, preferably a layer of adhesive (not shown in the drawings) isinterposed between member 22 and layer 40. Suitable adhesives must betransparent to the wavelengths of energy being accepted and reflected bythe display. Conveniently, an ultra-violet (UV) radiation curableadhesive is utilized as these adhesives can be made readily transparent,can be rapidly cured at room temperature, and are readily commerciallyavailable.

Representative ingredients forming the adhesive include, for example,reactive vinyl monomers such as the lower alkyl esters of acrylic andmethacrylic acids or polymers or prepolymers thereof. Vinyl monomersparticularly adapted for photopolymerization include, for example,methyl methacrylate, ethyl methacrylate, 2-ethyl hexyl methacrylate,butyl acrylate, isobutyl methacrylate; the corresponding hydroxyacrylates, e.g., hydroxy ethyl acrylate, hydroxy propyl acrylate,hydroxy ethyl hexyl acrylate; also the glycol acrylates, e.g. ethyleneglycol dimethacrylate, hexamethylene glycol dimethacrylate; the allylacrylates, e.g. allyl methacrylate, diallyl methacrylate; the epoxyacrylates, e.g. glycidyl methacrylate; and the aminoplast acrylates,e.g. melamine acrylate. Other ingredients include diallylphthalate,vinyl acetate, vinyl and vinylidene halides, N-vinyl pyrroleidone, andamides, e.g. methyl acrylamide, acrylamide, diacetone acrylamide,butadiene, styrene, vinyl toluene, and the like, and mixtures thereof.Specific preferred UV curable ingredients include acrylic acid,hydroxyethylacrylate, 2-ethylhexylacrylate, trimethylolpropanetriacrylate, glycerylpropoxytriacrylate, polyethylene glycol diacrylate,polyethylene oxides, and polyvinyl acetate. A wide variety of additionalcompounds may be used in forming the adhesive as those skilled in theart will appreciate.

Ultraviolet photosensitizers or sensitizers are combined with themonomers or prepolymers used to form the adhesive for achieving cure inthe presence of UV radiation. Useful UV sensitizers or photosensitizersinclude halogenated polynuclear ketones such as disclosed in U.S. Pat.No. 3,827,957; and organic carbonyl compounds selected from alkylphenones, benzophenones, and tricyclic fused ring compounds as disclosedin U.S. Pat. No. 3,759,807. Further useful UV sensitizers includecaxbonylated phenol nuclear sulfonyl chlorides, such as set forth inU.S. Pat. No. 3,927,959. Typically, at least about 0.5% by weight of theUV sensitizer, and preferably about 1-5% sensitizer, is added to theingredients and thoroughly mixed or otherwise dispersed in the liquidcarrier ingredients. The disclosures of these references are expresslyincorporated herein by reference.

With respect to the holographic lens elements, finally, it will beappreciated that such lens elements can be in any shape orconfiguration, though they preferably are square when viewed fromoverhead to maximize the fill factor.

The next item is rigid opaque spacer 42 which has outer surface 44 andinner surface 46. Spacer 42 has a matrix of apertures in registrationwith the matrix of discrete lens elements, e.g. lens elements 32-38,with upper surface 48 being in adjacency with layer 40. Again, spacer 42is rigid as is member 22 for providing structural integrity to thedisplay. Spacer 42 can be made of metal (e.g. aluminum), ceramicmaterial, polymeric material, or any other material that can be renderedopaque to the wavelengths of energy impinging upon the display. Whilethe apertures, e.g. aperture 48, can be a hole in spacer 42, theaperture additionally can be transparent material of the same ordifferent composition as the remaining opaque areas of spacer 42. FIG. 8shows an arrangement of apertures as would be seen when viewing thenovel display. As stated above, the size, density, and arrangement ofthe apertures (and, hence, pixels) can be determined by the displaymanufacturer.

Next, a matrix of discrete bimorph elements in registration with therigid opaque spacer apertures is provided. In FIG. 7, bimorph elements50-58 are shown. In particular, bimorph element 50 is in registrationwith aperture 48 which, in turn, is in registration with lens element32. Aperture 48 restricts light directed by lens 32 to strike bimorphelement 50 and not strike any other bimorph element of the matrix ofbimorph elements.

Bimorph element 50 can be seen in greater detail by reference to FIGS. 9and 10. With respect to FIG. 9, bimorph element 50 is seen to becomposed of piezo layers 60 and 62. The upper surface of piezo layer 60is coated with a continuous layer of metal 64 which preferably isconnected to ground 66 by lead 68 and on/in which diffraction pattern 65is created. With respect to FIG. 10, layer 76, including the outersurfaces of bimorphs 50, 52, and 78, is entirely coated with metal orother electrically material. Piezo layer 62 has its outer surface coatedwith a discrete layer of metal 70 which can be hooked to a source ofvoltage 72 by lead 74. With respect to FIG. 10, bimorphs 50, 52, and 78each have only their bottom surfaces metallized.

FIG. 10 also shows how the bimorph element array can be manufacturedfrom continuous bimorph sheet 76 by die-cutting three orthogonal sidesto form rectangular bimorphs 50, 52, and 78 which still are connected tosheet 76 by one side. This geometry permits each bimorph element to bedisplaced as the phantom position in FIG. 9 illustrates. It should beunderstood that the geometric configuration depicted in FIG. 10 isillustrative only. Other geometries easily can be envisioned.

Additionally with respect to FIG. 11, it will be observed thatpiezoelectric film element 100 is manufactured so that is can belengthened or contracted in-plane by application of a voltage thereto sothat the effective spacing of diffraction pattern 65 will be altered.For that matter, a transparent layer can be embossed, transparent layer64, and diffraction grating 65 created in transparent layer 64, asillustrated at FIG. 12.

Underneath bimorph layer 76 (FIG. 10) and its discrete bimorph elements50-58 can be placed printed wiring board (PWB) or circuit board 80 (FIG.7) which can be connected to leads 74 and 84-88 extending from thediscrete metallization layers, e.g. metallization layer 70, connectedtherewith. PWB 80, which suitably can be a multi-layer printed wiringboard, enables each discrete bimorph element via each respective lead tobe addressed individually.

Metallization of the discrete bimorph elements or of layer 76 (FIG. 10)can be applied by vapor deposition metallization techniques, liquidcoating techniques, and like techniques. It should be understood thatsuch metalized bimorph films are commercially available such as KYNAR®piezo film (polyvinylidene fluoride film, AMP Industries, Inc., ValleyForge, Pa.).

With specific reference to FIGS. 7, 9, and 11, it will be observed thatlight 26 (FIG. 7) incident on glass 22 passes thought lens element 32which directs the light through aperture 48 and onto bimorph element 50.A application of a positive voltage to bimorph element 50 results inelement 50 being deflected upwardly as shown by arrow 90 to the positionshown in phantom. Alternatively, bimorph element 100 (FIG. 11 ) could beelongated by application of the voltage. A selected band of light (e.g.,red) then would be reflected back by the metal layer 64 through aperture48 and into lens element 32. Lens element 32 then would focus the redlight onto upper surface 24 of glass 22 whose coating would attenuatethe red light on surface 24 to generate red pixel 30. It will beappreciated that deflection of bimorph element 50 downwardly byapplication of a negative voltage would result in blue light beinggenerated while green light would be generated when bimorph element isits relaxed state. The selection of voltages and colors in the abovedescription is for illustration purposes. Also, it will be appreciatedthat bimorph element 50 also can be moved into a position whereby nolight is reflected so that bimorph element 50 would act as its ownshutter. By addressing each bimorph element separately, pixels ofvarying color can be generated for static or dynamic graphic displays.

By simply making metallization layers 64 and 70 transparent, theassembly in FIG. 9 or 12 can operate in a transmission mode whereinlight striking transparent metallization layer 70 at an angle thenpasses though bimorph 50 and is diffracted by diffraction pattern 65 togenerate a given color, as described above.

An alternative embodiment to the construction set forth at FIGS. 7-12eliminates HOE/DOE 49 (FIG. 6) by incorporating its focusing functioninto a holographic diffractive element (HDE), as illustrated at FIGS.13-15. The HDE is created with a unique geometry such that itreflects/transmits a focused spectrally pure real image a short distancein front of it onto a diffuse surface. FIG. 13 illustrates this uniquegeometry for the construction of the hologram that provides a "selffocusing" pixel. Collimated, or slightly convergent, reference beam 104impinges on photographic plate 106 at angle θ from plate 106 normal(shown in phantom). Object beam 108 is focused by lens 110 onto groundglass element 112 behind which is plate 114 which contains slit 116through which object beam 108 passes. Object beam 108 passing throughslit 116 and diverges out over a single pixel and interferes withreference beam 104 to make a hologram that is recorded on film 106. Thepurpose of slit 116 is to cause the reconstruction beam to spectrallyseparate. The purpose of spherical lens 110 is to cause each spectralcolor to focus to a point. Distance d₁ between film 106 and plate 114need only be a few centimeters or less and slit 116 need only be about2-5 centimeters wide.

Thus, when a reference beam strikes developed film 106 in the conjugatedirection (from the opposite side in a direction towards the originalsource), a real image of the slit is reconstructed at a distance d₁ fromfilm 106. FIG. 14 illustrates how the reconstruction of the threeprimary colors can be accomplished by movement of film 116 in the mannerof element 50 (see FIG. 9) in the transmissive mode of operation (seeFIGS. 3a-d). Plate 114, which also contains a diffraction pattern andmovement force (for example, a bimorph with diffraction pattern asillustrated at FIG. 9), is placed a distance d₁ from glass plate 118.When reconstruction beam 120 strikes plate 114, the angle of incidencewill result in a color image of slit 116 being projected as a diffuse"dot" onto glass plate 118 for viewing by observer 122. As plate 114 isbent, the incidence angle will vary and so will the color projected. AtFIG. 15, opaque apertured plate 124 is placed a distance d₁ from plates124 and 126 for observer 122 to view a matrix of discreet coloredpixels.

With respect to other types of elements useful in practice of thepresent invention, reference is made to FIG. 16 wherein element 130carries diffraction grating 132. Plunger 134 tactilely abuts the freeend of element 130 which is fixed about pivot 136. Plunger 134 can bemade of an electrostrictive material, such as are commercially availablefrom AVX Corporation (Myrtle Beach, S.C.), e.g., Code C060210A,C060315A, C060020A, R020305A, etc.. See also, Uchino, et at., "Review:Electrostrictive Effect in Perovskites and its Transducer Applications",J. Matls. Sci., 16 (1981) 569-578. Alternatively, plunger 134 can bemade of a magnetostrictive material, such as are commercially availablefrom Edge Technologies, Inc. (Ames, Iowa), ETREMA Terfenol-D (an alloyof terbium, dysprosium, and iron). Additionally, electrostatic elementscan be used for plunger 134. See Younse, "Mirrors on a Chip", IEEESpectrum, Nov. 1993, pp. 27-31.

Yet other embodiments for deflection of the diffraction grating areillustrated at FIGS. 17-20. Referring to FIG. 17, film 138 carriesdiffraction grating 132. Below film 138 are magnets 140 and 142 withoppositely disposed North-South as illustrated. These magnets sit uponback 144 which may or may not be magnetic (e.g., iron). Element 138carries energizable coil 146 (or layers of coils, on the surface orembedded in the film) with axis perpendicular to the plane of the filmwhich coils can be laid down, for example, by tape-automated bonding(TAB) and are connected to an energy source (e.g., electrical source),not shown. Element 138 has pivot axis 148 perpendicular into the sideelevational view (into the paper) shown in FIG. 17. It is important tonote that the pivot or hinge point for film 138 can be at either end,the center of gravity, or at any other location, and film 138 rotate asillustrated herein. When the coils are energized, a magnetic couple iscreated, as indicated by magnetic flux lines 150, and element 138rotates about its pivot axis. If back 144 is magnetic, the fieldstrength of permanent magnets 140 and 142 is improved, thus the torque(magnetic moment) on coil 146 is increased. More discussion of thistechnique can be found in U.S. Pat. No. 5,295,031. It should be pointedout that multi-layer printed wiring board (PCB) 152 may be interposedbetween element 138 and magnets 140, 142 in order to provide a base forthe pivot axis of film 138 and to ease electrical connection of thecoils in film element 138. The torque on coil 146 can be represented bythe following equation: ##EQU2## where, θ=Angle between plane of coilwinding and flux direction at the coil plane

Amperes=Current in coil (amps)

Turns=Number of turns in coil

L=Length of coil turns along coil axis (meters)

B=Flux density at coil turns (Tesla)

Referring to FIG. 18, permanent magnets 140, 142 are disposed at theends of film 138. Magnetic flux lines 150 are created as shown. Thetorque on coil 146 is shown by arrow 154 (with the current in thedirection shown). PCB 152 is magnetic in this illustration. The torqueon coil 146 can be represented by the following equation: ##EQU3##where, Cos θ=1=Angle between plane of coil winding and flux direction atthe coil plane

Amperes=Current in coil (amps)

Turns=Number of turns in coil

L=Length of coil turns along coil axis (meters)

B=Flux density at coil turns (Tesla)

The embodiment depicted at FIG. 19 is like that at FIG. 18, except thatsteel back plate 144 replaces non-magnetic PCB 152. Such replacementyields flux lines 150a and 150b. Force, F, on coil 146 can berepresented by the electromotive force formula:

    F=B×L×i

where,

F=Force on coil

B=Flux density at coil turns (Tesla)

L=Length of coil turns along coil axis (meters)

i=Current in coil (amps)

The torque on coil 146 does depend upon the hinge (pivot) point. Thetorque, τ, for each applicable length of active winding can berepresented by the following formula:

    τ=F×r×2

where,

r is that winding's distance from the pivot (hinge) point

F=Force on coil

FIG. 20 is the HDE of FIG. 19 with multi-channel stereophonic soundaugmentation. Flux lines 156a and b can be seen in FIG. 20 to notparticipate in driving HDE 138. By inserting coils 158-162, it will beobserved that the magnetic flux lines in the region of these coils aresubstantially orthogonal to the current direction in the coils. Theresulting force, F, is, accordingly, orthogonal to both flux and currentas depicted at FIG. 20. The force again can be represented by theequation, F=B×1×i, as described above. Thus, one or more sound drivers(coils) can be incorporated into each pixel to drive films 164 and 166,which can transparent films (even the same layer as the holographiclens), glass plate, or a separate film layer. These films contain theelectrical conductors that lead from one sound driver to the next(electrically in series). Note, leakage flux 170-174 around coils158-162, respectively. Such leakage flux interconnects each adjacentsound driver assembly as shown at FIG. 22 where 178 is from a previouscoil and 176 is to the next coil.

Referring to FIG. 22, illustrates a coil plan view of a top and a bottomcoil arrangement which can be used for the embodiments illustrated atFIGS. 17-20. Contact pad 180 is connected to PCB 152 at the bottom sideof film 138 and is connected to another contact pad (not shown) on theupper side of film 138 by a through via. Conductive tracer 182 is on thetop side of film 138 while conductive tracer 184 is on the bottom sideof film 138 and terminates at contact pad 180. Both tracers terminate atthrough via 186 for making electrical connection from the top side tothe bottom side of film 138. Of course, other embodiments of thismagnetic coil technique will be readily realized by those skilled inthis art. For example, while moving coils are illustrated, such coilsmay be held stationary and moving magnets may be incorporated into theHDE.

The disclosure herein is illustrative of the present invention whichshould be understood to include various variations, modifications, andequivalents to those disclosed herein as those skilled in the art willappreciate. In this application, all references are incorporated hereinby reference.

We claim:
 1. A display comprising an element which carries a holographicdiffraction pattern which element is connected to a source energizablefor movement of said element, wherein said holographic diffractionpattern is moved by movement of said element and wherein movement ofsaid holographic diffraction pattern diffracts energy incident on saidholographic diffraction pattern to generate different select diffractedenergies from said holographic diffraction pattern.
 2. The display ofclaim 1, wherein said element comprises a bimorph element.
 3. Thedisplay of claim 2, wherein said diffraction pattern is embossed on saidbimorph element.
 4. The display of claim 3, wherein said embossedbimorph element reflects said diffracted energy.
 5. The display of claim3, wherein said embossed bimorph element is transmissive to saidincident energy to generate said diffracted energy.
 6. The display ofclaim 3, wherein said pattern is embossed directly on said bimorphelement.
 7. The display of claim 3, wherein said pattern is embossed ona film which is laminated to said bimorph element.
 8. The display ofclaim 1, wherein said element is connected to an electrical or magneticsource for movement of said element.
 9. The display of claim 2, whereinsaid bimorph element is connected in parallel to said electrical source.10. The display of claim 2, wherein said element is connected in seriesto said electrical source.
 11. The display of claim 3, wherein saidelement is connected to an electrical source for movement of saidelement.
 12. The display of claim 11, wherein said bimorph element isconnected in parallel to said electrical source.
 13. The display ofclaim 11, wherein said bimorph element is connected in series to saidelectrical source.
 14. A matrix of the display of claim
 1. 15. A matrixof the display of claim
 3. 16. The display of claim 3, wherein saidbimorph is formed from layers of polyvinylidene fluoride (PVDF).
 17. Thedisplay of claim 1, wherein said element has a pivot axis and a pair ofends each of which bear electrically energizable coils which aremagnetically coupled with a pair of magnets which are spaced apart fromsaid element ends, whereby energizing said coils causes said element torotate about its pivot axis.
 18. The display of claim 17, wherein saidmagnets are magnetically coupled through a magnetic back.
 19. Thedisplay of claim 17, wherein said magnets are disposed beneath saidelement ends.
 20. The display of claim 17, wherein said magnets aredisposed adjacent to and at said element ends.
 21. The display of claim20, wherein a sound film is placed above at least one of said pair ofmagnets with another electrically energizable coil placed between saidsound film and said magnet in an orientation whereby the electromotiveforce generated by current in said another coil is substantiallyorthogonal to said sound film, whereby energizing said another coilcauses said sound film to vibrate to generate sound.
 22. A transmissivediffractive display, which comprises:(a) an outer transparent rigidmember having an outer surface and an inner surface, said memberrestricting reflected energy incident on its inner surface; (b) adiscrete lens element having an apparent outer surface and an apparentinner surface and being adjacent said outer transparent rigid member,(c) a rigid opaque spacer having an outer surface and an inner surface,and having an aperture in registration with said discrete lens elementand disposed in adjacency to the lens element apparent inner surface;and (d) a transmissive discrete element in registration with said rigidopaque spacer aperture, said discrete element having an inner surfaceand an outer energy diffractive surface adjacent said spacer aperturewhich diffractive surface bears a diffraction pattern for diffractingenergy passed therethrough when said element is in a relaxed state, saiddiscrete element connected to an electrical source effective to generateselected excited states therefor wherein said element is physicallydisplaced from its location in a relaxed state, said element permittinga different diffraction of energy passed therethrough when said elementis in an excited state;whereby energy transmitted through thediffraction pattern is diffracted and then passes through said aperturethrough said lens element which focuses said diffracted energy onto thetransparent rigid member.
 23. The display of claim 22, wherein saiddiffraction pattern is embossed in said element.
 24. The display ofclaim 22, wherein said diffraction pattern is embossed in a transmissivelayer which is laminated to said element.
 25. The display of claim 23,wherein said outer transparent rigid member outer surface is coated witha non-linear coating to restrict energy incident of the transparentrigid member inner surface.
 26. The display of claim 22, wherein saiddiscrete lens element is one or more of a holographic lens element or adiffractive lens element.
 27. The display of claim 22, wherein saidelement is a bimorph element.
 28. The display of claim 22, wherein saidelement has a pivot axis and a pair of ends each of which bearelectrically energizable coils which are magnetically coupled with apair of magnets which are spaced apart from said element ends, wherebyenergizing said coils causes said element to rotate about its pivotaxis.
 29. The display of claim 28, wherein said magnets are magneticallycoupled through a magnetic back.
 30. The display of claim 28, whereinsaid magnets are disposed beneath said element ends.
 31. The display ofclaim 28, wherein said magnets are disposed adjacent to and at saidelement ends.
 32. The display of claim 31, wherein a sound film isplaced above at least one of said pair of magnets with anotherelectrically energizable coil placed between said sound film and saidmagnet in an orientation whereby the electromotive force generated bycurrent in said another coil is substantially orthogonal to said soundfilm, whereby energizing said another coil causes said sound film tovibrate to generate sound.
 33. The display of claim 27, wherein saidbimorph is formed from layers of polyvinylidene fluoride (PVDF).
 34. Thedisplay of claim 22, wherein the function of items (b)-(d) comprises:afilm having said outer diffractive surface which is the function of item(d) and a focused developed holographic image of said aperture which isthe function of items (b) and (c), the film being a distance from saidmember (a) effective for focusing said image on the inner surface ofmember (a).
 35. A reflective diffractive display, which comprises:(a) anouter transparent rigid member having an outer surface and an innersurface, said member passing incoming energy incident on its outersurface but restricting reflected energy incident on its inner surface;(b) a discrete lens element having an apparent outer surface and anapparent inner surface and being adjacent said outer transparent rigidmember, said lens element focusing energy passed through said outertransparent rigid member and incident thereon; (c) a rigid opaque spacerhaving an outer surface and an inner surface, and having an aperture inregistration with said discrete lens element and disposed in adjacencyto the lens element apparent outer surface; and (d) an element inregistration with said rigid opaque spacer aperture, which element hasan outer energy reflecting surface adjacent said spacer aperture whichreflecting surface bears a diffraction grating which permits reflectanceof selected diffracted energy incident on said outer element surfacewhen said element is in a relaxed state, said element connected to anelectrical source effective to generate selected excited states thereforwherein said element is physically displaced from its location in arelaxed state, said element permitting reflectance of differentdiffracted energy incident on said element outer surface when saidelement is in an excited state;whereby energy incident on thetransparent rigid member outer surface passes therethrough and isfocused through said aperture and incident on the diffraction grating,selected energy then is reflected back from said diffraction gratingthrough said aperture through said lens element which focuses saidselected energy onto the transparent rigid member outer surface.
 36. Thedisplay of claim 35, wherein said diffraction pattern is embossed insaid element.
 37. The display of claim 35, wherein said diffractionpattern is embossed in a transmissive layer which is laminated to saidelement.
 38. The display of claim 35, wherein said element is a bimorphelement.
 39. The display of claim 35, wherein said element has a pivotaxis and a pair of ends each of which bear electrically energizablecoils which are magnetically coupled with a pair of magnets which arespaced apart from said element ends, whereby energizing said coilscauses said element to rotate about its pivot axis.
 40. The display ofclaim 39, wherein said magnets are magnetically coupled through amagnetic back.
 41. The display of claim 39, wherein said magnets aredisposed beneath said element ends.
 42. The display of claim 39, whereinsaid magnets are disposed adjacent to and at said element ends.
 43. Thedisplay of claim 42, wherein a sound film is placed above at least oneof said pair of magnets with another electrically energizable coilplaced between said sound film and said magnet in an orientation wherebythe electromotive force generated by current in said another coil issubstantially orthogonal to said sound film, whereby energizing saidanother coil causes said sound film to vibrate to generate sound. 44.The display of claim 35, wherein said bimorph is connected in series tosaid electrical source.
 45. The display of claim 35, wherein saidbimorph is formed from layers of polyvinylidene fluoride (PVDF).
 46. Thedisplay of claim 35, wherein the function of items (b)-(d) comprises:afilm having said outer diffractive surface which is the function of item(d) and a focused developed holographic image of said aperture which isthe function of items (b) and (c), the film being a distance from saidmember (a) effective for focusing said image on the inner surface ofmember (a).
 47. A method for generating different select diffractedenergies from energy incident on a display, which comprises:(a)providing an element which carries a diffraction pattern which elementis connected to a source energizable for movement of said element,wherein said diffraction pattern is moved by movement of said elementand wherein movement of said diffraction pattern diffracts energyincident on said diffraction pattern to generate diffracted energy fromsaid diffraction pattern; (b) directing energy onto said embosseddiffraction pattern; and (c) controlling the movement of said elementwith said energizable source to vary the effective spacing of thediffraction pattern to control the select diffracted energy generated.48. The method of claim 47, wherein said display comprises a diffractionpattern embossed on a bimorph element which bimorph element is connectedto an electrical source for movement of said bimorph element.
 49. Themethod of claim 48, wherein said directed energy comprises visible lightand said bimorph element is controlled to generate select colors. 50.The method of claim 48, wherein said display is composed of a matrix ofsaid bimorph elements for providing a matrix of select diffractedenergy.
 51. The method of claim 49, wherein said display is composed ofa matrix of said bimorph elements for providing a matrix of selectcolors.
 52. The method of claim 48, wherein said embossed elementreflects said directed energy.
 53. The method of claim 48, wherein saidembossed element is transmissive to said directed energy.
 54. The methodof claim 47, wherein said element has a pivot point at its center ofgravity and a pair of ends each of which bear electrically energizablecoils which are magnetically coupled with a pair of magnets which arespaced apart from said element ends, whereby energizing said coilscauses said element to rotate about its pivot point.
 55. The display ofclaim 54, wherein said magnets are magnetically coupled through amagnetic back.
 56. The display of claim 54, wherein said magnets aredisposed beneath said element ends.
 57. The display of claim 54, whereinsaid magnets are disposed adjacent to and at said element ends.
 58. Thedisplay of claim 57, wherein a sound film is placed above at least oneof said pair of magnets with another electrically energizable coilplaced between said sound film and said magnet in an orientation wherebythe electromotive force generated by current in said another coil issubstantially orthogonal to said sound film, whereby energizing saidanother coil causes said sound film to vibrate to generate sound. 59.The method of claim 47, wherein said display provided comprises:(a) anouter transparent rigid member having an outer surface and an innersurface, said member restricting reflected energy incident on its innersurface; (b) a discrete lens element having an apparent outer surfaceand an apparent inner surface and being adjacent said outer transparentrigid member, (c) a rigid opaque spacer having an outer surface and aninner surface, and having an aperture in registration with said discretelens element and disposed in adjacency to the lens element apparentinner surface; and (d) a transmissive discrete element in registrationwith said rigid opaque spacer aperture, said discrete element having aninner surface and an outer energy diffractive surface adjacent saidspacer aperture which diffractive surface bears a diffraction patternfor diffracting energy passed therethrough when said element is in arelaxed state, said discrete element connected to an electrical sourceeffective to generate selected excited states therefor wherein saidelement is physically displaced from its location in a relaxed state,said element permitting a different diffraction of energy passedtherethrough when said element is in an excited state;whereby energytransmitted through the diffraction pattern is diffracted and thenpasses through said aperture through said lens element which focusessaid diffracted energy onto the transparent rigid member.
 60. Thedisplay of claim 59, wherein the function of items (b)-(d) comprises:afilm having said outer diffractive surface which is the function of item(d) and a focused developed holographic image of said aperture which isthe function of items (b) and (c), the film being a distance from saidmember (a) effective for focusing said image on the inner surface ofmember (a).
 61. The method of claim 47, wherein said display providedcomprises:(a) an outer transparent rigid member having an outer surfaceand an inner surface, said member passing incoming energy incident onits outer surface and restricting reflected energy incident on its innersurface; (b) a discrete lens element having an apparent outer surfaceand an apparent inner surface and being adjacent said outer transparentrigid member, said lens element reflecting energy passed through saidouter transparent rigid member and incident thereon from the lenselement apparent outer surface onto the outer transparent rigid memberwith such energy then being reflected back through said lens element;(c) a rigid opaque spacer having an outer surface and an inner surface,and having an energy aperture in registration with said discrete lenselement and disposed in adjacency to the lens element apparent innersurface; and (d) an element in registration with said rigid opaquespacer aperture, which element has an outer energy reflecting surfaceadjacent said spacer aperture which reflecting surface bears adiffraction grating which permits reflectance of selected diffractedenergy incident on said outer element surface when said element is in arelaxed state, said element connected to an electrical source effectiveto generate selected excited states therefor wherein said element isphysically displaced from its location in a relaxed state, said elementpermitting reflectance of different diffracted energy incident on saidelement outer surface when said element is in an excited state;wherebyenergy incident on the transparent rigid member outer surface passestherethrough and is directed through said aperture and incident on thediffraction grating, selected energy then is reflected back from saiddiffraction grating through said aperture through said lens elementwhich focuses said selected energy onto the transparent rigid memberouter surface.
 62. The display of claim 61, wherein the function ofitems (b)-(d) comprises:a film having said outer diffractive surfacewhich is the function of item (d) and a focused developed holographicimage of said aperture which is the function of items .(b) and (c), thefilm being a distance from said member (a) effective for focusing saidimage on the inner surface of member (a).
 63. A display comprising apiezoelectric film which carries a holographic diffraction pattern whichpiezoelectric film is connected to an electrical source for movement ofsaid piezoelectric film, wherein said holographic diffraction pattern ismoved by movement of said piezoelectric film and wherein movement ofsaid holographic diffraction pattern diffracts energy incident on saidholographic diffraction pattern to generate different select diffractedenergies from the holographic diffraction pattern.
 64. The display ofclaim 63, wherein said embossed piezoelectric film reflects saiddiffracted energy.
 65. The display of claim 63, wherein said embossedpiezoelectric film is transmissive to said incident energy to generatesaid diffracted energy.
 66. The display of claim 63, wherein saidpiezoelectric film is connected in parallel to said electrical source.67. The display of claim 63, wherein said piezoelectric film isconnected in series to said electrical source.
 68. A matrix of theembossed piezoelectric films of claim
 63. 69. The display of claim 63,wherein said piezoelectric film is polyvinylidene fluoride (PVDF).
 70. Adisplay comprising a diffraction pattern embossed on an element whereinsaid element has a pivot point at its center of gravity and a pair ofends each of which bear electrically energizable coils which aremagnetically coupled with a pair of magnets which are spaced apart fromsaid element ends, whereby energizing said coils causes said element torotate about its pivot point to diffract energy incident thereon togenerate diffracted energy from the element.
 71. The display of claim70, said magnets are magnetically coupled through a magnetic back. 72.The display of claim 70, wherein said magnets are magnetically coupledthrough a magnetic back.
 73. The display of claim 70, wherein saidmagnets are disposed beneath said element ends.
 74. The display of claim70, wherein said magnets are disposed adjacent to and at said elementends.
 75. The display of claim 74, wherein a sound film is placed aboveat least one of said pair of magnets with another electricallyenergizable coil placed between said sound film and said magnet in anorientation whereby the electromotive force generated by current in saidanother coil is substantially orthogonal to said sound film, wherebyenergizing said another coil causes said sound film to vibrate togenerate sound.